I'm not sure exactly how it is in the UK, but in America the large defense contractors have an immense amount of influence within the government (both with elected officials and in the various administrations). It's been that way for quite a while and for the most part has kept growing no matter whether Democrats or Republicans are in charge.

It's doubly frustrating because there ARE real potential threats out there, but this system of perverse incentives tends to waste massive amounts of money and labor on military projects of questionable usefulness, unnecessary wars, and intelligence projects of questionable legality. Sadly, China is spending its resources on its military far more efficiently... not a good thing when that growing power is run by an authoritarian and ruthless government. This control-freak obsession on keeping the US government the most powerful nation on Earth at all costs is paradoxically setting the stage for future weakness and vulnerability for others to exploit. Needless to say I got a lot of flak for this opinion in my old career 😏